A woman has been arrested in connection with the attempted murder of a prison officer in a bomb attack in Belfast on Friday, March 4th.
PSNI detectives detained the woman (35) in the Belfast area on Thursday.
She was taken to Musgrave Serious Crime Suite for questioning.
A court has also granted detectives an additional 24 hours to question three men, aged 34, 39 and 45, who were arrested on Sunday in relation to the incident.
A prison officer (52) required surgery after an explosive device detonated under the van he was driving on March 4th.
A group calling itself the New IRA claimed to have carried out the attack.
Statement
In a statement to the BBC, the dissident republican group reportedly said the officer was targeted because he was involved in training other guards at Maghaberry high security jail, near Lisburn.
They said the officer was one of a number on a list of potential targets and the attack arose from a dispute over the treatment of dissident republican inmates.
The group also claimed to have used the plastic explosive Semtex and a commercial detonator in the attack.
Following the blast, police commanders expressed fears it could be the first of a number of dissident republican attacks to mark the centenary of the Easter Rising.
Additional reporting: PA